Ok well.. i jus bought my second rx7 its a 91 NA... n i rememebr in my old fc that it had a screw on the radiaor to release air from the coolant lines.. but i cant find any on this one.. i cant find any anywhere.. does it come with one?.. the reason it bugs me is because the buzzard keeps going off and i filled it up but i can still feel air in the lines... the overflow tank never moves so i dont think the seals r bad.. and the cap was recently replaced.. car only has 80k miles so its not all that old.. does anyone know where this screw to release air is at?.. or if it even has one? ill post some pics of the engine bay asap...

 

Start with a Mazda brand radiator cap.
I once had a Stant radiator cap whose relief valve on the bottom didn't clear the filler neck, so the system couldn't draw from the overflow tank on cool down.

Also an S5 with a healthy cooling system will almost run at zero pressure.
I had another split cap seal once & didn't discover any problems for months.

 

Damn, zero pressure? My S4 runs with significant pressure in it. I have some generic radiator caps for it though. The old ones were leaking on me.

Try idling it with the fill cap (top one) off, and just fill it up as the level drops. Make sure your heater is on full as well, in case there's air buried back in the heater core. It took me a few days to finally get all the air out of my cooling system when I flushed it.

-=Russ=-

 

k ill try all those right now.. and i beleive it has a mazda radiator cap..

 

ok well i tried a lot of things.. and same thing... i cant find a lil air release screw... and also i noticed that the buzzard turns on b4 the thermostat opens... onece it opens, after its fully wrmed.. then it doesnt say it needs coolant.. but then if i let it sit for a while... then the cycle starts again..

 

How do you figure? Thermal expansion of water no longer in effect? How about the lower boiling point of water at no operating pressure?

If you have no poressure in your cooling system, S4 or S5, something is wrong.

I have personally owned four S5's, and worked on many, many more, and none of them ran at zero operating pressure for the cooling system.

 

unless ur running no thermostat?... i dunno jus a question...ok well i can see my car when its cold that it doesnt have water in the top hose.. jus air... thats not right... and the cap is brand new.. im going to check the resivior line make sure it isnt kinked or sumthin..

 

hrm u know what seals r bad i think... damn.. oh well.. heres some pics of my car...